Maderas. Ciencia y Tecnología

Effects of design configuration on decay initiation and progression in non-durable wood

Rod Stirling — 2025-12-16

Wood used above ground and exposed to moisture may be vulnerable to decay. The initiation and rate of decay are influenced by several factors, including substrate type, moisture and temperature. The design and geometry of wood components affect moisture dynamics and may therefore influence both the initiation and progression of decay. This study evaluated the impact of nine different design configurations on the durability of wood components in a field experiment conducted at three North America sites with distinct climates. The tested variables included specimen volume, the presence of impermeable surface coatings, and the arrangement of appressed boards. Significant effects on both decay initiation and severity were observed, with water-trapping features such as appressed boards and sealed surfaces associated with earlier onset and more extensive decay over a fixed period. The results suggest that longer service life may be achieved by avoiding design features that retain moisture or inhibit drying.

Variación anatómica en la madera de clones de Eucalyptus grandis y sus propiedades dinámicas

Christian Bulman Hartkopf — 2026-01-13

El uso creciente de plantaciones de rápido crecimiento para fines estructurales exige criterios confiables para evaluar la calidad mecánica de nuevos materiales genéticos mediante métodos no destructivos. No obstante, la elevada proporción de madera juvenil y la variabilidad anatómica limitan la interpretación de estas técnicas cuando no se comprende su base estructural.

El objetivo de este estudio fue analizar la variación anatómica de la madera y su relación con la densidad básica y las propiedades dinámicas determinadas por resonancia acústica en cinco clones mejorados de Eucalyptus grandis de 11 años. Se evaluó el espesor y proporción de pared celular, longitud de fibra, ángulo microfibrilar, diámetro y frecuencia de poros, considerando su variación entre clones y dentro del fuste.

Los resultados mostraron que el diámetro y la frecuencia de poros permiten identificar la presencia de madera madura, mientras que la proporción de pared celular explicó la variación de la densidad básica. El ángulo microfibrilar presentó una fuerte relación con la velocidad del sonido y el módulo de elasticidad dinámico.

En conclusión, la integración del análisis anatómico con la resonancia acústica mejora la interpretación de las propiedades dinámico-mecánicas y aporta una herramienta aplicada para la evaluación estructural no destructiva y la selección genética de clones de Eucalyptus

Ajuste de los factores de diseño en compresión axial para madera laminada encolada del álamo

Lía Caren Meyer — 2026-01-15

La compresión axial en elementos de madera laminada encolada (glulam) requiere de un dimensionamiento preciso que considere tanto las propiedades mecánicas del material como los efectos de esbeltez. En este contexto, los reglamentos vigentes presentan limitaciones al aplicar valores únicos para los factores de estabilidad (C_P) y de inestabilidad (K_c), sin contemplar las variaciones propias de cada especie ni los modos de falla por pandeo. El presente estudio aborda esta problemática mediante barras de madera laminada de Populus deltoides, con el objetivo de ajustar los parámetros “c” y “βc” que intervienen en el cálculo de dichos factores. Se llevaron a cabo ensayos de compresión axial en un total de 320 probetas en el rango de esbeltez comprendido entre 30 a 100. A partir de los resultados experimentales de las tensiones de rotura del percentil 5 % y la resistencia a compresión paralela a las fibras, se determinaron los valores óptimos de los parámetros “c” y “βc”. El reglamento argentino usa un único valor de c=0,9 para piezas de madera laminada encolada de aplicación práctica. Sin embargo, este valor evidencia la necesidad de ajustes para mejorar el dimensionamiento en elementos comprimidos, obteniendo un valor menor de “c”. Por otro lado, el criterio europeo con βc = 0,1 tiende a sobrestimar las cargas de compresión. No obstante, el mayor valor de βc determinado con el programa experimental, presentó una mejor correlación para todas las esbelteces, reduciendo las sobrestimaciones de las cargas a compresión. Los resultados confirman que ajustar los parámetros “c” y “βc” mejora significativamente la precisión del dimensionado y optimizando el diseño en elementos comprimidos.

Decay and leaching resistance of spruce and larch woods treated with preservatives following different incising pretreatments

Davut Bakır — 2026-03-02

The objective of this study was to determine the extent to which different incising pretreatments can increase decay and leaching resistance of Picea orientalis (oriental spruce) and Larix decidua (european larch) woods. To this purpose, mechanical, biological, and laser incision treatments were applied to sapwood samples of these refractory wood species to enhance permeability. After the incision treatments, cross sections of the samples were sealed with a polyurethane-based paint commonly used in marine applications to minimize excessive uptake of impregnation chemicals. Subsequently, the treated samples were impregnated using a vacuum method with an alkaline copper quat (ACQ) solution (Celcure C₄), a copper (Cu)-based preservative. The impregnated spruce and larch samples with and without different incision treatments were then subjected to leaching. Non-pretreated and non-impregnated samples, pretreated and non-impregnated samples, non-pretreated and impregnated samples (leached and non-leached), and pretreated and impregnated samples (leached and non-leached) spruce and larch were exposed to brown rot (Tyromyces palustris) and white rot (Trametes versicolor) fungi for 16 weeks. The highest Cu content (ppm) in spruce before and after leaching was generally observed in samples treated with laser incision; in larch, the highest values were obtained with biological incision. Moreover, incising treatments did not increase Cu leaching in larch, while only biological incision increased leaching in spruce. Decay resistance against both fungal species generally improved in blocks impregnated with Cu compounds following mechanical and laser incising treatments, both before and after leaching. In addition, leaching reduced decay resistance in the control and in laser incised samples exposed to brown rot fungus.

The utilisation of turpentine and moss oil as epoxy hardeners for bio-based epoxy nanocomposite coatings

Ilknur Babahan Bircan — 2026-03-02

Despite the growing interest in bio-based epoxy systems, there remains a significant research gap in developing fully bio-derived curing agents that can replace conventional BPA-based epoxy hardeners while maintaining adequate mechanical and physical performance on wood substrates. The objective of this study was to investigate the potential of new bio-based, bisphenol A-free epoxide nanocomposite coatings for wood surfaces, as a replacement for commercially available coating containing bisphenol A. In addition, the surface properties of these coatings were evaluated.

This study involves the use of environmentally friendly, bisphenol A-free, new bio-based epoxy coatings and their nanocomposite derivatives, in which both the resin and hardener are derived from natural sources. The study is original in its use of sustainable natural resources in the coatings industry, as well as in the development of cost effective and readily available systems compared to those derived from petroleum. Futhermore, this

he research is is the first to employ moss oil and turpentine oil as hardeners in epoxy resin curing reactions.

The results obtained with these two oils, which share a similar chemical structure, were compared. The study also investigates the effect of nanoparticles on the physical and mechanical properties of the bio-based coatings. In this study, novel bio-based epoxide nanocomposite coatings for wood surfaces were prepared using a tung oil-based epoxide resin, which was cured with moss and turpentine oil for the first time. Moss oil and turpentine oil were utilised as epoxy hardeners. The wood species selected for this investigation was Fagus orientalis (oriental beech). Furthermore, as prospective substitutes for bisphenol A, the characteristics of the new bio-based epoxide coatings, specifically the system obtained using moss oil and turpentine oil as hardening agent, were evaluated in relation to their nanocomposite derivatives doped with carbon nanoparticles (fullerene, carbon nanotubes, and graphene) for application on wooden substrates. Following the application of various coating materials to the wood surface, evaluations were conducted on the mechanical and physical properties of the wood. This included measurements of water absorption, t oven-dry density, and compression strength parallel to the grain of Fagus orientalis (oriental beech). The findings revealed that all test specimens showed oven-dry density values higher than those recorded for the control group. After the final absorption period, all coated specimens demonstrated a reduction in water absorption compared to the control.. Each coated specimen also exhibited a higher compression strength parallel to the grain than the control group. Consequently, it was established that the implementation of innovative bio-based nanocoatings has the potential to enhance the mechanical and physical properties of Fagus orientalis (oriental beech) wood.

Eco-friendly protection of pine wood using copper nanoparticles biosynthesized from Cleistocalyx operculatus leaf extracts

Tram Tran Thi Bao — 2026-03-04

This research investigates the eco-friendly biosynthesis of copper nanoparticles (CuNPs) from Cleistocalyx operculatus (water banyan) leaf extracts for the sustainable preservation of pine wood Pinus kesiya (khasi pine). The study specifically targets protection against common wood-decaying fungi, including Aspergillus flavus ATCC 9643, Fusarium oxysporum ATCC 48112, and Penicillium citrinum ATCC 9849, as well as termites. CuNPs were synthesized under optimized conditions: 80 °C for 30 minutes using a rotary evaporator, at pH 11, with 20 mM copper sulfate, and a 1.5:1 plant extract to precursor ratio. Comprehensive characterization using UV-Vis spectroscopy confirmed a prominent absorption peak at 595 nm. Scanning Electron Microscopy and Transmission Electron Microscopy further validated their spherical morphology, high crystallinity, and an average size of 2 ± 1 nm. Wood durability was evaluated through laboratory tests of fungal and termite resistance To assess the effects of different CuNPs treatments on fungal resistance and termite resistance, a one-way ANOVA was employed. Significant differences were found among the treatment groups (P<0,05). Duncan's multiple range test was performed using SPSS Statistics version 26, with statistical significance set at α = 0,05. The findings demonstrated a clear concentration-dependent efficacy of CuNPs. Treated wood samples exhibited significantly enhanced fungal and termite resistance, displaying notably reduced weight loss (approximately 10-15 %) compared to untreated controls (20-30 %). Furthermore, even at the lowest tested dosage, a substantial termite mortality rate of 43,17 % was observed, highlighting the potent bioactivity of the biosynthesized CuNPs. These results support the potential of Cleistocalyx operculatus-mediated CuNPs as an environmentally sustainable substitute for conventional, often harmful, wood preservatives. This green approach offers a sustainable alternative for wood protection and shows promise for broader applications of eco-friendly nanomaterials.

Image based colorimetric characterization of scrub induced color changes in UV printed and water transfer printed MDF boards

Mehmet Budakçı — 2026-03-05

Conventional colorimetric evaluation methods remain inadequate for accurately characterizing scrub-induced color changes on UV-printed and water transfer-printed decorative coatings applied to MDF after chemical resistance testing; therefore, this study proposes an image-based colorimetric characterization approach using an Image Processing-Based Scrub Tester to quantitatively assess such changes under simulated domestic chemical exposure. For this study, 8 mm thick Medium-Density Fiberboard sheets with a bright white, polyvinyl chloride-coated Medium-Density Fiberboard, high-gloss acrylic coating Medium-Density Fiberboard, Medium-Density Fiberboard lam, and Medium-Density Fiberboard sheets treated with polyurethane, cellulose-based, water-based and acrylic paints were utilized. A carbon fiber-patterned organic finish was applied to the surfaces of the pre-treated Medium-Density Fiberboard sample using ultraviolet printing and water transfer printing (WTP) techniques, followed by scrubbing testing with various domestic cleaning agents in compliance with Turkish Standards. As part of the picture evaluation process in this study, digital picture of the samples was captured after and before the scrubbing process. Color measurements were then analyzed based on L*, a*, and b* coordinates, conforming to the Commission Internationale de l'Éclairage (CIE L*a*b*) color system, utilizing a newly developed evaluation technique. From the outcomes of the study, it was observed that the overall color shift of the water transfer printing samples was 124,63% more than the ultraviolet printed samples. To assess the precision of the Image Processing-Based Scrub Tester's color measurement system developed in this research, its results were benchmarked against those from a different color tester. As a result, the findings strongly suggest that the color test analysis performed with Image Processing-Based Scrub Tester, together with the developed software, has the potential to serve as an alternative to industrial testing equipment.

Comparative evaluation of three-way mortise-and-tenon joint designs considering mechanical strength and machinability

Yuqing Yang — 2026-03-09

It is still a challenge to manufacture traditional three-way Zongjiao mortise-and-tenon joints using modern CNC-based machines. This study aimed to improve the structure of the Zongjiao mortise-and-tenon joint, a commonly used three-way corner joint in wood furniture, to better align with modern manufacturing practices. First, four improved mortise-and-tenon joint types were designed, and their appearances were evaluated. Secondly, mechanical tests and numerical analyses were conducted to compare the four improved types and two previous types using bending strength and load difference ratio (DR) between the two horizontal members of the joint. Subsequently, the machinability of all types of joints was evaluated through processing time (PT), cutting force (CF), and number of effective programs (NEP). The results showed that the maximum bending strength of the Zongjiao M-T joint was observed in Type D, and the load DR between the two horizontal members was 13,79. The improved Type D has the lowest milling CF of 182 N and the minimum PT of 32 minutes with the least NEP. Through a comprehensive analysis of all the above indices evaluated, it was found that the improved Type D of Zongjiao mortise-and-tenon joint was superior to others, considering appearance, mechanical strength, and machinability. This study provided a paradigm for optimizing wood furniture joints, which can also be applied to other wood products.

Experimental characterization of briquettes produced from Eucalyptus bark with cassava starch binder

Maria Fernanda Felippe Silva — 2026-03-10

Brazil has a vast area of planted forests, which makes it the second largest producer of bark as a by-product. Several alternatives have been studied for the reuse of this residue; however, little attention has been given to the use of forest residues, such as bark, in the energy sector for briquette production and to the main variables involved in this process. The aim of this work was to evaluate the viability of producing briquettes from Eucalyptus bark. The briquettes were produced and characterized according to American and Brazilian standards, evaluating two different particle sizes and the addition of cassava starch. The briquettes produced from Eucalyptus bark show potential for use, although attention should be paid to their ash content. In particular, the treatment produced with a 12-mesh granulometry and the addition of cassava starch showed the best chemical, energetic, physical, and mechanical properties. The production of briquettes from Eucalyptus bark demonstrates the feasibility of reusing forest residues for bioenergy production.

Classification of four wood species using terahertz time-domain spectroscopy THZ-TDS

Jimy Frank Oblitas Cruz — 2026-03-17

Terahertz time-domain spectroscopy (THz-TDS) combined with chemometric techniques was investigated as a non-destructive method for species classification in wood samples from four different species. For this purpose, samples were introduced into the THZ-TDS spectrometer chamber purged with dry nitrogen, and spectra were collected at wave intervals from 0,1 THz to 10 THz to evaluate the samples. It was obtained that in the range between 0,1 THz and 1,7 THz, there is higher differentiation of the samples, being this the best range to generate classification models. After the chemometric analysis, the Support Vector Machine algorithm achieved an accuracy rate of 91 % in classifying the four wood species. Finally, it was demonstrated that THz spectroscopy can be used for quantitatively complex natural organic materials such as wood.

Anatomical responses in apricot wood structure caused by Valsaria insitiva

Oľga Mišíková — 2026-03-30

Understanding anatomical responses in various tree species to fungi causing gummosis is limited. In this article, wood samples from an apricot tree (Prunus armeniaca) with severe gummosis and branch dieback were studied macroscopically and microscopically to determine the response of woody tissues to the infection. The fungi species Valsaria insitiva was determined visually by the signs of the disease and by cultivating clean cultures. Macroscopical examination found wedge and arch shaped necroses running along the growth rings under the bark necroses and sunken lesions. Microscopical examination found small black fruiting bodies of the fungus on the bark. Vessels and libriform fibers were blocked by gum, thus blocking the water and nutrients flow to the branches and causing the dieback. Sites with fungi infection were compartmentalized and this was discussed according to the CODIT model. Oxidized ray parenchyma was visible in tangential and cross sections of the wood; calluses were covering the infected areas. Compartmentalizing the infections by releasing gum into vessel lumina, restricting the flow of nutrients and water in the tree thus drying it out is a way of protection of the tree against the pathogens. Apoplexy of apricots is an acute disease and can be very extreme in some cases. The studied tree had signs of compartmentalization of the infection, but the infection was spreading faster than new tissues were formed.

Influence of particle size and blending ratio on the physical and mechanical properties of falcata sawdust-recycled LDPE wood-plastic composites

Juanito Jr. Jimenez — 2026-04-16

The increasing accumulation of wood and plastic waste necessitates the development of sustainable, value-added materials such as wood-plastic composites (WPCs). This study investigated the feasibility of utilizing Falcataria moluccana (falcata) sawdust as a reinforcing filler in a recycled low-density polyethylene (LDPE) matrix. WPCs were fabricated via twin-screw extrusion using three sawdust particle sizes—P20R40 (0,840 - 0,400 mm), P40R60 (0,400 - 0,250 mm), and P60 (<0,250 mm)—at blending ratios of 30:70 and 40:60 (sawdust:LDPE, by weight). Physical properties, including relative density, moisture content, water absorption, and thickness swelling, were evaluated alongside mechanical performance according to ASTM standards. The results demonstrated that the incorporation of sawdust produced WPCs with physical stability and hygroscopic properties comparable to or superior to those of the pure recycled LDPE control. Mechanical analysis revealed a significant reinforcement effect; the inclusion of sawdust enhanced both the tensile and flexural strength and modulus of the composites. Specifically, finer sawdust particles (<0,250 mm) and a 30:70 sawdust-to-LDPE ratio yielded the optimal overall mechanical performance. However, impact strength tests indicated that the wood filler increased material brittleness, as the neat LDPE significantly outperformed all WPC treatments in energy absorption. Overall, this study concludes that falcata sawdust is a viable natural fiber for reinforcing recycled LDPE, offering a sustainable pathway for upcycling waste into rigid composite materials, provided that applications account for the inherent reduction in impact resistance.

Laminated bamboo lumber beams: An evaluation of structural behavior and bonding quality

João Vítor Felippe Silva — 2026-04-17

Laminated bamboo lumber is a lignocellulosic composite with a wide range of applications in construction. Despite its growing use in structural applications, the structural behavior of laminated bamboo lumber has not been sufficiently investigated through advanced numerical modelling approaches, and the influence of species–adhesive combinations on bonding performance remains insufficiently understood. This lack of integrated numerical–experimental studies represents a critical research gap for the reliable structural analysis of bamboo-based elements. This work aimed to address this gap by numerically and experimentally evaluating laminated bamboo lumber elements submitted to three-point bending tests and by assessing the bonding performance of four distinct species-adhesive combinations (i.e. Dendrocalamus asper, Phyllostachys pubescens). The physical and mechanical properties of the lamellas were obtained from the experimental characterization of bamboo. A finite element modeling was developed to simulate the structural response, incorporating orthotropic behavior and physical non-linearity. The constitutive model adopted for bamboo followed Hill's criterion, simulating elastic-plastic behavior through bilinear curves. The numerical and experimental results showed good agreement, and the model was able to simulate the behavior of beams in bending, including the identification of critical stresses regions along the element. The species-adhesive combinations showed high delamination and shear strength at the glue lines. The results demonstrate the capability of the proposed numerical framework to predict the bending behavior of laminated bamboo lumber and highlight the importance of appropriate species–adhesive selection, contributing to the development of reliable design and manufacturing strategies for structural bamboo products.

Axial variation of color and Shore D hardness in Cedrus libani wood

Uğur Özkan — 2026-04-17

This study examines the limited understanding of axial variation in color and hardness properties of Cedrus libani wood. In this context, the variation in color parameters and Shore D hardness across heart, heartwood, and sapwood sections was systematically investigated. Wood disc samples obtained from different axial positions of a 102-year-old tree were used to evaluate color properties, including lightness (L*), redness (a*), and yellowness (b*), together with hardness values. A total of 480 measurements were conducted across the three anatomical sections. The results demonstrated that both color and hardness properties vary systematically along the axial direction of the tree. Sapwood exhibited higher lightness values, whereas heart and heartwood showed comparatively lower L* values. Redness was more pronounced in heartwood and heart sections, while yellowness values were relatively similar across sections, with slightly higher values observed in the heart. In terms of mechanical properties, Shore D hardness increased from sapwood toward the center of the tree, reaching its maximum in the heart section. Additionally, axial differences were evident, with upper sections displaying higher hardness values compared to lower sections. These findings provide new insights into the axial variation of physical and mechanical properties in Cedrus libani wood, contributing to a better understanding of its material behavior. This knowledge is important for optimizing utilization strategies and improving performance-based classification of wood depending on its position within the tree.

Experimental analysis of axial variation in physical and mechanical properties of Detarium microcarpum wood and its potential for sustainable utilization

Zulkarnain Abdul Samed — 2026-04-17

This study addresses the limited availability of scientific data on the physical and mechanical properties of Detarium microcarpum (sweet detar) wood, which constrains its evaluation as a potential timber resource. An experimental characterization was conducted using wood samples obtained from three mature trees in Walateng-Goziir, Nandom Municipality, Ghana. The stems were sectioned into bottom, middle, and top portions to assess axial variation. Physical properties (moisture content, oven-dry density, volumetric shrinkage, and swelling) and mechanical properties (modulus of elasticity, modulus of rupture, compression parallel to grain, and shear strength) were determined at 12 % moisture content using standardized methods. The results showed significant axial variation (p < 0,05) across all measured properties. Moisture content increased from 13,78 % at the base to 16,35 % at the top, while oven-dry density decreased from 775,84 kg/m³ to 670,28 kg/m³. Mechanical properties also declined along the stem height, with modulus of elasticity decreasing from 6453,78 MPa to 5996,44 MPa. These findings provide empirical data that contribute to the scientific understanding of Detarium microcarpum (sweet detar) wood and support its evaluation as a lesser-used species with potential for timber applications.

Impact of nano-aluminum-oxide impregnation, densification, and vapor pre-treatment on the physical and mechanical properties of white willow wood

Hamid Reza Taghiyari — 2026-04-21

Fast-growing wood species are often characterized by low density, unsatisfactory mechanical properties, and poor biological durability. Therefore, various modification techniques have been tested to improve these disadvantages. The aim of this research work was to investigate the effects of densification of Salix alba (white willow) under hot pressing for 15 and 30 minutes on its physical and mechanical properties. Vapor pre-treatment for four and six hours was also applied to mitigate the negative effects of cracks and checks caused by breakage in wood cell wall under pressure. Markedly, separate sets of specimens were impregnated with aluminum oxide nano-suspension to evaluate if an increase in thermal conductivity would improve the properties of wood. The results indicated that densification significantly enhanced both the physical and mechanical properties of the wood. The four-hour vapor pre-treatment demonstrated the optimal improving results in both hot pressing durations. Though impregnation of specimens with the nano-suspension improved some properties (including spring back, hardness, and physical properties), most of the studied mechanical properties did not show any statistically significant improvement. Therefore, it was concluded that densifying willow wood for 15 minutes with a four-hour vapor pre-treatment yields optimal results. The enhancement in mechanical properties due to nano-aluminum oxide was not substantial enough to justify the associated costs, and thus, its use is not recommended for industrial applications.